The psoas major: The most amazing muscle you've never heard of

By DANIELA VELÁZQUEZ | The Tampa Tribune
Published: August 6, 2011

It doesn't have thousands of songs devoted to it like the heart. And it doesn't have the epic story of love, war and country that goes with the Achilles' heel.

But even though you've likely never heard of it, your psoas major is one of the most important muscles in your body.

Usually called the psoas (pronounced "so-az"), this muscle and your body's main hip flexor run along your spine, from the diaphragm to pelvis, wrapping around your hip bones.

There's a good chance the pain you have in your lower back, hip and groin means there's something amiss with your psoas. It also could be responsible for a litany of other conditions, including poor circulation and digestive problems.

Every time you walk, run, bike or otherwise use your lower body, your psoas moves and guides the connection between your torso and your legs.

In addition to its key role in keeping you upright, the psoas is also the first muscle to recognize your primal fear and stress instincts, says somatic expert Liz Koch.

That causes the psoas muscle to stay contracted much of the time, pulling on other muscles and creating tension in other places of your body.

"You want a good fight or flight response, but you don't want to be on call 24/7," Koch says. "That's the reason (your body is) exhausted all the time."

The psoas is one of three muscles in the iliopsoas group and one of two muscles that connects your torso to your legs. The iliacus lines the bowl of the pelvis. These two muscles are constantly in a state of balance to keep you upright. (The third muscle — the psoas major — is considered a devolving muscle and is present in less than half of the population.)

Because of its proximity to the spine, the psoas is also deeply connected to all the parts of the nervous system, making it the main storehouse for all sorts of trauma, the emotional leftovers of our fight or flight response.

"The psoas is this crazy muscle that was not working when we were quadrupeds," says Brooklyn-based Jonathan FitzGordon, who teaches people how to walk with proper alignment.

"The psoas is a pulley; it is holding the spine up."

FitzGordon says he sees all sorts of issues related to the tenderest part of our bodies, literally the human filet mignon, including poor foot circulation, leg-length discrepancies and having one foot arch or shoulder higher than the other. And for all you desk dwellers out there, don't think your psoas gets a break; sitting in a chair keeps the psoas contracted, and thus tighter.

I didn't know anything about this muscle until a few years ago. I jumped and twisted to make an amazing catch in a game of Ultimate Frisbee; and somewhere between the Frisbee landing in my hand and my feet hitting the ground, I tweaked my back.

Within an hour, I couldn't stand up straight. I called in sick to work and got an appointment with a trusted massage therapist. She suggested releasing my psoas.

"So-az? Uhh, OK."

"Just breathe. It will hurt," she said, as she pushed down on my lower belly and pelvis.

I saw flashes of mustard yellow and grey as I tried to breathe more than wince. I felt nauseous. And then, I felt my back release without pain.

To address psoas-related issues we have to do the opposite of what we're used to: We have to relax.

"Everyone needs to stop," says FitzGordon. "If you don't relax, it never gets a break."

For information, visit FitzGordon's website at www.corewalking.com, or Koch's website, www.coreawareness.com, for free articles and videos about working with your psoas.